scholarly journals Screening of Model Animals for Experimental Infection with Equine Cyathostomes

2018 ◽  
Vol 49 (1) ◽  
pp. 17-20
Author(s):  
Š. Scháňková ◽  
I. Langrová ◽  
I. Jankovská ◽  
J. Vadlejch ◽  
Z. Čadková ◽  
...  
Keyword(s):  
Life Cycle ◽  
Experimental Infection ◽  
Larval Stage ◽  
Rattus Norvegicus ◽  
Oryctolagus Cuniculus ◽  
Meriones Unguiculatus ◽  
Laboratory Animals ◽  
Suitable Model ◽  
Cavia Porcellus ◽  
Mongolian Gerbils

Abstract Various laboratory animals – mice (Mus musculus) of six strains, rabbits (Oryctolagus cuniculus), guinea pigs (Cavia porcellus), rats (Rattus norvegicus), and Mongolian gerbils (Meriones unguiculatus) were experimentally infected with larvae of small strongyles (Cyathostominae), obtained from horse faeces and cultured to the infective larval stage L3. The attempt to transfer cyathostome larvae was aimed at developing a model for the investigation of different aspects of the life cycle and biology of these nematodes in the laboratory. Some animals were immunized (hydrocortisone) for the duration of the study. The laboratory animals were orally infected with 2–10 thousand sheathed or ex-sheathed L3 larvae of mixed cyathostome species. All attempts to inoculate any animal failed; there was no larval development in the experimental rodents and it can be stated that none of the investigated animals may serve as a suitable model host for horse nematodes of the subfamily Cyathostominae.

scholarly journals Speech Sound Discrimination by Mongolian Gerbils

2021 ◽  
Author(s):  
Carolin Juechter ◽  
Rainer Beutelmann ◽  
Georg M. Klump
Keyword(s):  
Speech Sound ◽  
Meriones Unguiculatus ◽  
Suitable Model ◽  
Mongolian Gerbils ◽  
Speech Sounds ◽  
Signal To Noise ◽  
Response Latencies ◽  
Human Speech ◽  
Perceptual Maps ◽  
Sound Discrimination

The present study establishes the Mongolian gerbil (Meriones unguiculatus) as a model for investigating the perception of human speech sounds. We report data on the discrimination of logatomes (CVCs - consonant-vowel-consonant combinations with outer consonants /b/, /d/, /s/ and /t/ and central vowels /a/, /aː/, /ɛ/, /eː/, /ɪ/, /iː/, /ɔ/, /oː/, /ʊ/ and /uː/, VCVs - vowel-consonant-vowel combinations with outer vowels /a/, /ɪ/ and /ʊ/ and central consonants /b/, /d/, /f/, /g/, /k/, /l/, /m/, /n/, /p/, /s/, /t/ and /v/) by young gerbils. Four young gerbils were trained to perform an oddball target detection paradigm in which they were required to discriminate a deviant CVC or VCV in a sequence of CVC or VCV standards, respectively. The experiments were performed with an ICRA-1 noise masker with speech-like spectral properties, and logatomes of multiple speakers were presented at various signal-to-noise ratios. Response latencies were measured to generate perceptual maps employing multidimensional scaling, which visualize the gerbils' internal representations of the sounds. The dimensions of the perceptual maps were correlated to multiple phonetic features of the speech sounds for evaluating which features of vowels and consonants are most important for the discrimination. The perceptual representation of vowels and consonants in gerbils was similar to that of humans, although gerbils needed higher signal-to-noise ratios for the discrimination of speech sounds than humans. The gerbils' discrimination of vowels depended on differences in the frequencies of the first and second formant determined by tongue height and position. Consonants were discriminated based on differences in combinations of their articulatory features. The similarities in the perception of logatomes by gerbils and humans renders the gerbil a suitable model for human speech sound discrimination.

Cryptosporidium ratti n. sp. (Apicomplexa: Cryptosporidiidae) and genetic diversity of Cryptosporidium spp. in brown rats (Rattus norvegicus) in the Czech Republic

Parasitology ◽  
2020 ◽  
pp. 1-14
Author(s):  
Jana Ježková ◽  
Jitka Prediger ◽  
Nikola Holubová ◽  
Bohumil Sak ◽  
Roman Konečný ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Rattus Norvegicus ◽  
Clinical Signs ◽  
Small Subunit ◽  
Meriones Unguiculatus ◽  
Biological Data ◽  
Mongolian Gerbils ◽  
Genotype I ◽  
Laboratory Rats ◽  
Small Subunit Rdna

Abstract The diversity and biology of Cryptosporidium that is specific for rats (Rattus spp.) are not well studied. We examined the occurrence and genetic diversity of Cryptosporidium spp. in wild brown rats (Rattus norvegicus) by microscopy and polymerase chain reaction (PCR)/sequencing targeting the small subunit rDNA (SSU), actin and HSP70 genes. Out of 343 faecal samples tested, none were positive by microscopy and 55 were positive by PCR. Sequence analysis of SSU gene revealed the presence of Cryptosporidium muris (n = 4), C. andersoni (n = 3), C. ryanae (n = 1), C. occultus (n = 3), Cryptosporidium rat genotype I (n = 23), Cryptosporidium rat genotype IV (n = 16) and novel Cryptosporidium rat genotype V (n = 5). Spherical oocysts of Cryptosporidium rat genotype I obtained from naturally-infected rats, measuring 4.4–5.4 μm × 4.3–5.1 μm, were infectious to the laboratory rats, but not to the BALB/c mice (Mus musculus) nor Mongolian gerbils (Meriones unguiculatus). The prepatent period was 3 days post infection and the patent period was longer than 30 days. Naturally- and experimentally-infected rats showed no clinical signs of disease. Percentage of nucleotide similarities at the SSU, actin, HSP70 loci between C. ratti n. sp. and the rat derived C. occultus and Cryptosporidium rat genotype II, III, IV, and V ranged from 91.0 to 98.1%. These genetic variations were similar or greater than that observed between closely related species, i.e. C. parvum and C. erinacei (93.2–99.5%). Our morphological, genetic and biological data support the establishment of Cryptosporidium rat genotype I as a new species, Cryptosporidium ratti n. sp.

Phoronida

2017 ◽  
Author(s):  
Judith Fuchs
Keyword(s):  
Life Cycle ◽  
Small Group ◽  
Larval Stage ◽  
Intertidal Zone ◽  
Marine Invertebrates ◽  
Tree Of Life ◽  
General Morphology ◽  
Family Level ◽  
Planktonic Larval Stage

This chapter describes the taxonomy of Phoronida, a small group of exclusively marine invertebrates found in most of the world's oceans from the intertidal zone to about 400 metres depth. Phoronids are meroplanktonic with a planktonic larval stage usually less than 2 mm in length and a benthic adult whose length ranges from a few cm up to 50 cm. The chapter covers their life cycle, ecology, and general morphology. It includes a section that indicates the systematic placement of the taxon described within the tree of life, and lists the key marine representative illustrated in the chapter (usually to genus or family level). This section also provides information on the taxonomic authorities responsible for the classification adopted, recent changes which might have occurred, and lists relevant taxonomic sources.

scholarly journals Bioavailability of β-carotene (βC) from purple carrots is the same as typical orange carrots while high-βC carrots increase βC stores in Mongolian gerbils(Meriones unguiculatus)

2006 ◽  
Vol 96 (2) ◽  
pp. 258-267 ◽  
Author(s):  
Mandy Porter Dosti ◽  
Jordan P. Mills ◽  
Philipp W. Simon ◽  
Sherry A. Tanumihardjo
Keyword(s):  
Public Health ◽  
Vitamin A ◽  
Phenolic Acids ◽  
Health Problem ◽  
Public Health Problem ◽  
Meriones Unguiculatus ◽  
Mongolian Gerbils ◽  
Alternative Source ◽  
Β Carotene

Vitamin A (VA) deficiency is a worldwide public health problem. Biofortifying existing sources of β-carotene (βC) and increasing dietary βC could help combat the issue. Two studies were performed to investigate the relative βC bioavailability of a βC supplement to purple, high-βC orange, and typical orange carrots using Mongolian gerbils (Meriones unguiculatus). In study 1, which used a traditional bioavailability design, gerbils (n32) received a diet containing orange, purple, or white carrot powder, or white carrot powder +a βC supplement. In study 2, which included βC-biofortified carrots, gerbils (n 39) received orange, high-βC orange, purple, or white carrot powder in their diet. Both studies lasted 21 d and the gerbils were killed to determine the effect of carrot type or supplement on serum and liver βC, α-carotene, and VA concentrations. Liver stores of βC or VA in the gerbils did not differ between orange and purple carrot diets when equal amounts of βC from each of the diets were consumed (P>0·05). Both the orange and purple carrot diet resulted in higher liver VA compared with the supplement (P<0·05). High-βC carrots resulted in more than 2-fold higher βC and 1·1 times greater VA liver stores compared with typical orange carrots (P<0·05). These results suggest that high-βC carrots may be an alternative source of VA to typical carrots in areas of VA deficiency. Second, phenolics including anthocyanins and phenolic acids in purple carrot do not interfere with the bioavailability of βC from purple carrots.

scholarly journals Experimental Infection of Two Species of Wrasse With The Digenean Proctoeces Subtenuis

1963 ◽  
Vol 43 (1) ◽  
pp. 113-123 ◽  
Author(s):  
R. F. H. Freeman
Keyword(s):  
Life Cycle ◽  
Experimental Infection ◽  
Parasite Population ◽  
Scrobicularia Plana ◽  
Vertebrate Hosts ◽  
Ctenolabrus Rupestris

Two species of wrasse, Ctenolabrus rupestris (L.) and Crenilabrus melops (L.) were experimentally infected with the digenean Proctoeces subtenuis (Linton) collected from Scrobicularia plana (da Costa). The fishes were killed 1-24 days after infection, and the parasite population of their guts examined. About 20 % of the introduced parasites survived for 2-3 days, but the degree of infection decreased with time, the smallest specimens surviving longest. No significant differences were found between parasites from invertebrate and experimental vertebrate hosts.P. major Yamaguti, 1934, and P. insolitus (Nicoll, 1915) are declared synonymous with P. subtenuis (Linton, 1907The bearing of these results on the life cycle of P. subtenuis is discussed

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